1. Field of the Invention
This invention relates to an antenna, more particularly to a multi-frequency inverted-F antenna for a portable electronic device.
2. Description of Prior Art
Wireless communication devices, such as cellular phones, notebook computers, electronic appliances, and the like, are normally equipped with an antenna that serves as a medium for transmission and reception of electromagnetic signals, such as date, audio, image, and so on. However, more and more portable electrical devices tend to miniaturization. Accordingly, antenna used in the portable electrical device need to tend to miniaturization.
Taiwanese patent No. 563274 discloses a multi-frequency inverted-F antenna that comprises: a conductive radiating element extending in a longitudinal direction and having opposite first and second ends lying in the longitudinal direction; a conductive grounding element spaced apart from the radiating element in a transverse direction relative to the longitudinal direction; a conductive interconnecting element extending between the radiating and grounding elements and including first, second, and third parts, the first part being electrically connected to the radiating element at a feeding point between the first and second ends of the radiating element, the second part being offset from the first part in the longitudinal direction and being electrically connected to the grounding element, the third part electrically interconnecting the first and second parts; and a feeding line electrically connected to the interconnecting element.
However, the multi-frequency antenna has relatively big size in height direction. Accordingly, many notebooks or other portable electronic devices do not have enough space to install such PIFA antenna.